Adding a rear EVAPORATOR......

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Adding a rear EVAPORATOR......

Postby JReeves_21 » Tue Aug 01, 2017 12:58 pm

Hello fellas, I have a degree in automotive technology and was a tech for a handful of years before purchasing my own shop. Now, I am a shop owner and general automotive junkie. I have done plenty of custom work with fuel/brake/coolant lines ect. Never with A/C. I'm not some foremost expert of a/c but as a technician I have a working knowledge.

I told you all that so you didn't think I was some kid wasting anyone's time. I have a customer, who would LOVE me if I could figure out a way to add a rear a/c unit to her Chevy Express van for her dogs. She loves her dogs and wants them to be cooler. So I told her I would do some research. I was going to attempt to mount an electric rooftop RV unit to the vehicle but I quickly found out that was not feasible, and was cost prohibitive.

So I would like to attempt to install a rear evaporator in my personal vehicle to see how it goes and then quote her on her A/C job.

My test subject will be my beloved 1997 Chevy Blazer LT 4 door. This thing is perfect, everything works and its rust free. I will drive it for a long time and I figured why not try to make it a little more comfortable while learning a little bit about A/C at the same time.

I am fine with tying the rear blower into the front, so there will never be a time the rear A/C is off while the front is on. I know there is a fear of all the oil collecting in the rear if the rear blower is off.

My questions will to get this conversation started will be:

Does anyone make a complete evaporator/blower unit?

Will I need a TXV at the rear unit?

Will I need to upgrade my condenser or compressor?

How do I calculate the necessary amount of refrigerant needed the new larger system?

I know that's alot to consume but if anyone wants to chime in please feel free, if you want to call me crazy or stupid thats fine too.

Thanks in advance guys.
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Re: Adding a rear EVAPORATOR......

Postby bohica2xo » Tue Aug 01, 2017 5:15 pm

Aftermarket rear units in conversion vans used to be a common thing.

The site sponsor ACKITS has been in the business of making aftermarket A/C stuff for decades, and made a lot of that equipment. The catalog has changed over the years, but here is one example - A/C & Heat:

Tim at AC Kits can set you up with the "T" fittings, evaporator etc.

G Van kits are probably more common than most actually. G vans have pretty good sized condensers, but an upgrade might be in order depending on climate.

For the little Blazer, I would wait for Tim to weigh in.

Rear systems use a TXV, and you can shut the fan down if you want.

Refrigerant charge will depend on lots of things, but we can walk you through the charge issues once you have a solid plan & parts list.

A fun project. I did a few E250's in the 1979 era. TV, Icebox, chairs, table... Rear unit really cools the back well if you insulate & finish the interior.

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